Bayer's Investigational Riociguat Meets Primary Endpoint in Phase III Study of Patients with Chronic Thromboembolic Pulmonary Hypertension (CTEPH)
WAYNE, N.J., Oct. 23, 2012 -- Bayer HealthCare today announced data from the Phase III CHEST-1 trial evaluating its investigational drug riociguat in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH) or with persistent or recurrent pulmonary hypertension (PH) after surgery. The results showed the CHEST-1 study met its primary endpoint by demonstrating a statistically significant improvement in the six-minute walk distance (6MWD). In the study, patients treated with riociguat showed an improvement of 46 meters (95%-CI [25-67 meters] p<0.0001) compared to placebo. The results were presented as a late-breaking abstract in an oral abstract session at CHEST 2012, the annual meeting of the American College of Chest Physicians (ACCP) in Atlanta, Georgia (Abstract No. 1462924).
Chronic thromboembolic pulmonary hypertension (CTEPH) is a life-threatening disease in which blood clots and thromboembolic occlusion of pulmonary vessels leads to an increased pressure in the pulmonary arteries.
"These study results with investigational riociguat are encouraging because it is the first randomized Phase III trial in which a drug treatment has demonstrated significant improvement in 6MWD in patients with inoperable CTEPH or with persistent or recurrent pulmonary hypertension (PH) after surgery," said lead investigator, Professor Hossein Ardeschir Ghofrani, University Hospital Giessen and Marburg, Germany. "Results from the Phase III development program suggest that riociguat may be a potential new option in CTEPH."
The ten most frequently reported treatment-emergent adverse events with riociguat vs. placebo were: headache (25% vs. 14%), dizziness (23% vs. 13%), peripheral edema (16% vs. 21%), cough (5% vs. 18%), dyspepsia (18% vs. 8%), nasopharyngitis (15% vs. 9%), dyspnea (5% vs. 14%), nausea (11% vs. 8%), diarrhea (10% vs. 5%) and vomiting (10% vs. 3%).
In the CHEST-1 trial, riociguat also showed statistically significant improvements in secondary endpoints including pulmonary vascular resistance (PVR) (p<0.0001), N-terminal prohormone brain natriuretic peptide (NT-proBNP) (p<0.0001) and WHO functional class (FC) (p=0.0026). Secondary endpoints that did not achieve statistical significance were observed in time to clinical worsening (TTCW) (p=0.1724), Borg dyspnea score (p=0.0035), European quality of life 5-dimensions questionnaire (EQ-5D) (p<0.0001) and living with pulmonary hypertension questionnaire (LPH) (p=0.1220).
"We are pleased to present the data from the Phase III CHEST-1 trial," said Pamela A. Cyrus, M.D., Vice President and Head of U.S. Medical Affairs, Bayer HealthCare Pharmaceuticals. "There is an unmet medical need for CTEPH patients who are unable to undergo surgery, or who have persistent or recurrent PH after surgery."
CHEST (Chronic Thromboembolic Pulmonary Hypertension sGC-Stimulator Trial) is a Phase III trial to assess the efficacy and safety of oral riociguat in the treatment of patients with either inoperable chronic thromboembolic pulmonary hypertension or pulmonary hypertension (PH) which has persisted or reoccurred after pulmonary endarterectomy (PEA). CHEST is a multi-center, multi-national program with active centers in 26 countries. The program includes a randomized, double-blinded, placebo-controlled trial phase (CHEST-1) and an open label extension trial phase (CHEST-2).
In the CHEST-1 study, 261 patients with inoperable CTEPH or with persistent or recurrent pulmonary hypertension after PEA were randomized and treated with either riociguat or placebo orally for 16 weeks. Riociguat was titrated, over a period of eight weeks in doses of 0.5 mg increments, from 1.0 mg up to 2.5 mg, three times a day. After the titration phase, patients were followed up for another eight weeks on their last dose to complete CHEST-1. Patients from both arms then had the option of participating in the open label extension study (CHEST-2) after completing an eight-week blinded sham titration. CHEST-2 is continuing to investigate riociguat in CTEPH patients. Results of CHEST-2 will be presented at an upcoming scientific congress in 2013.
Riociguat (BAY 63-2521), discovered and developed at the Bayer research laboratories, is an investigational oral soluble guanylate cyclase (sGC) stimulator. In addition to CTEPH, riociguat is currently under investigation for other types of pulmonary hypertension, including pulmonary arterial hypertension (PAH). The PATENT study is a Phase III trial assessing riociguat in both treatment-naive PAH patients and those pre-treated with an endothelin receptor antagonist or an oral, inhaled or subcutaneous prostanoid. Data from the first phase of the study, PATENT-1, was also presented at the "Late Breaking Abstracts" (Abstract 1462924) session at the CHEST congress.
Riociguat is an investigational agent and is not approved by the FDA, EMA or other health authorities.
About Bayer HealthCare Pharmaceuticals Inc.
Bayer HealthCare Pharmaceuticals Inc. is the U.S.-based pharmaceuticals business of Bayer HealthCare LLC, a subsidiary of Bayer AG. Bayer HealthCare is one of the world's leading, innovative companies in the healthcare and medical products industry, and combines the activities of the Animal Health, Consumer Care, Medical Care, and Pharmaceuticals divisions. As a specialty pharmaceutical company, Bayer HealthCare provides products for General Medicine, Hematology, Neurology, Oncology and Women's Healthcare. The company's aim is to discover and manufacture products that will improve human health worldwide by diagnosing, preventing and treating diseases.
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 Ghofrani, HA. et al. Riociguat for the treatment of inoperable chronic thromboembolic pulmonary hypertension: a randomized, double-blind, placebo-controlled study (CHEST-1). CHEST 2012, Atlanta, USA. Oral presentation. Abstract 1462924.
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